It is known to use phase contrast angiography MRI techniques to provide magnetic resonance (MR) angiographic projection images indicating a flow of bodily fluids through various body passages for medical diagnostic purposes. Techniques such as phase contrast angiography provide projection images, for example, though an entire anatomical thickness of patient, and allow high quality magnetic resonance (MR) angiograms of arterial and venous structures to be obtained along one or more selected projection axes and with a selected direction of flow sensitivity. Typically, a bipolar gradient pulse is used to encode phase shifts due to velocity of imaged fluid flows
It is also known to track an invasive device fitted with a radio frequency (RF) coil within a patient using MR signals that are excited within the entire patient. The excitations are detected by the coil of the invasive device to provide coil position, and, accordingly, device position information. The position information may be superimposed on an MR image of a region of interest or otherwise made available to an operator of the invasive device. Such MR tracking techniques may include the use of excitation multiplexing schemes, such as Hadamard modulation, to reduce a number of excitations needed to locate the device within the body of the patient. MR tracking may be performed relatively more rapidly than other MRI techniques over an entire three dimensional volume of the patient.